Removal of rhodamine 6g dyestuff from wastewater by adsorption onto ELM (Ulmus glabra) and Mulberry (Morus alba) sawdust

In this thesis, elm (KAT) and mulberry (DT) sawdust have been used as low cost, abundant and environmentally friendly adsorbents in removal of Rhodamine 6G (R6G), which is a cationic dyestuff and tried to present an alternative to existing expensive methods. The characterization of adsorbents was performed by methods such as Boehm titration, pHpzc and moisture content determination. The effects of various factors such as aqueous solution pH, equilibrium time, amount of adsorbent and initial R6G concentration that may affect the adsorption efficiency of R6G on KAT and DT were investigated and optimum experimental conditions were determined. The effects of ionic strength on the adsorption process were also investigated. The optimum aqueous solution pH for the adsorption of R6G on both adsorbents was 7.0 and the equilibrium time was 180 minutes. Adsorption kinetics was followed by the second order kinetic model and the experimental data showed a good fit to both Langmuir and Freundlich isotherm models. The monolayer adsorption capacity of KAT and DT was found to be 50.5 and 31.8 mg g-1, respectively, using the Langmuir isotherm model. As a result of comparison with other adsorbents given in the literature, it was concluded that elm and mulberry sawdust may be an effective and low cost option for dye removal.